Method and Apparatus for Single-Axis Cross-Sectional Scanning of Parts

• US 20110069300A1
• Filed: 05/15/2009
• Published: 03/24/2011
• Est. Priority Date: 05/19/2008
• Status: Active Grant

• Current Assignee: Craig D. Crump
• Original Assignee: Craig D. Crump
• Inventors: Braegelman, Dan, Crump, Craig D., Kahler, Brad
• Granted Patent: US 9,324,129 B2
• Time in Patent Office: Days
• US Class Current: 356/36
• CPC Class Codes: G01N 1/286 involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising microtomes G01N1/06; pulverising in general B02C; mixing in general B01F
• CPC Class Codes: G01N 2001/061 Blade details
• CPC Class Codes: G01N 2001/366 Moulds; Demoulding
• CPC Class Codes: G06T 17/10 Constructive solid geometry [CSG] using solid primitives, e.g. cylinders, cubes
• CPC Class Codes: G06T 3/00 Geometric image transformations in the plane of the image

Abstract

Improved methods and apparatus for cross-sectional scanning of parts employ a scanning station in which the focal plane of the scanning apparatus never moves in the vertical direction, i.e., the direction in which the stage of the part/potting combination moves. Distinct steps of material removal and scanning alternate with an intermediate step of moving the part/potting combination in the vertical direction after a surface layer has been removed, thus placing the newly-created surface back into the non-moving focal plane for the next scanning step. A removal station (not the stage carrying the part/potting combination) repeatedly moves into and out of the field of view of the scanning station between scanning steps. The material removal station is specially configured to remove the desired surface layer of the part/potting combination and the created debris, without requiring the separate environment characteristic of previous commercial applications.

Claims

1. A system for scanning a substantially transparent part having an outer surface, comprising:

a data gathering station, a material removal station, and a table providing only vertical movement of the part relative to the data gathering station along a vertical path;

in which the part is encased in a potting material to form an assembly;

the material removal station removing a portion of the assembly to expose a surface.

2. The system of claim 1, in which the data gathering station comprises at least one of:

an image data acquisition device for successively acquiring images of the part after removal of a predetermined contour; and

an electronic device operatively associated with the image data acquisition device for receiving and storing the images.

3. The system of claim 1, in which the material removal station comprises at least one of:

a tool constructed and arranged to remove a predetermined contour of material from the part; and

a drive mechanism constructed and arranged to provide relative horizontal movement between the tool and the part.

4. The system of claim 1, in which the table holds the part and further comprises a drive mechanism constructed and arranged to provide vertical movement between the table and the data gathering station along the vertical path.

5. A method for producing electronic data representations of an object having a plurality of surfaces, the method comprising:

encasing the object within a preselected encasing material to form an encasement, such encasing being done so that all surfaces of the object are coated with the encasing material and so that the encasing material substantially fills all interior volumes of the object;

removing successively from the encasement a plurality of layers of material, each layer of material removed having predetermined dimensions of length, width and depth and a predetermined geometric shape, so as to expose an encasement surface, and assigning a value to each layer representative of its elevation within the object;

acquiring an electronic representation of selected exposed encasement surfaces after a predetermined layer has been removed; and

processing each electronic representation to create a predetermined electronic representation of each the encasement surface.

6. The method of claim 5, in which the selected electronic representation is a solid model of the object and in which the processing step includes converting each electronic representation into a layered point cloud representative of the object.

7. The method of claim 5, in which the method further comprises lofting a surface onto each layered point cloud.

8. The method of claim 5, in which the method further comprises importing each the layer into CAD space and stacking the layers according to their assigned elevation value.

9. The method of claim 5, and further including creating a solid between adjacent layers.

10. The method of claim 5, in which the selected electronic representation is a solid model of the object.

11. The method of claim 5, in which the selected electronic representation is a surface model of the object.

12. The method of claim 5, in which the contour removing step removes contour of material such that successively exposed surfaces of the object are substantially parallel to each other, the method further including:

identifying a feature of interest in the object; and

orienting the object such that the exposed surfaces of the object are non-parallel to the feature of interest so that at least one exposed surface extends through the feature of interest.

13. The method of claim 5, in which the acquiring step includes scanning each encasement surface using a scanner to create a scanned image of each encasement surface.

14. The method of claim 5, in which the selected electronic representation is a surface model of the object and in which the processing step includes convening each electronic representation into a line an drawing defining the perimeter edges of the internal and external edges of the object.

15. The method of claim 14, in which the processing step further includes stacking the line art drawings and lofting a surface thereon.

16. The method of claim 14, in which the processing step further includes converting the line art drawings into a vector data file.

17. The method of claim 16, in which the processing step further includes importing the vector data file into 3D CAD space and lofting a surface thereon.

18. The method of claim 5, in which the layers have upper and lower surfaces and a substantially uniform thickness, the upper and lower surfaces being substantially parallel to each other.

19. The method of claim 5, in which the electronic representation is a raster planar image and in which the processing step further includes importing the raster planar image into 3D CAD space and converting the imported images into a solid model of the object.

20. The method of claim 5, in which the layers have upper and lower surfaces being substantially parallel to each other and in which the layers increase in thickness as successive layers of the encasement are removed to form each the predetermined contour.

21. The method of claim 5, in which the layers have upper and lower surfaces being substantially parallel to each other and in which the layers decrease in thickness as successive layers of the encasement are removed to form each the predetermined contour.

22. The method of claim 5, in which the predetermined contour has a substantially uniform thickness.

23. Apparatus for producing electronic data representations of an object, the object being formed from at least one material, the apparatus comprising:

a material removal station;

a data gathering station having a fixed position focal plane; and

a stage movable in only a vertical direction perpendicular to the fixed position focal plane;

in which the material removal station comprises;

means for removing a predetermined layer of material from the object;

in which the data gathering station comprises;

means for successively imaging the object after removal of a predetermined layer; and

means for storing data gathered by the means for imaging; and

in which the stage comprises;

a table for holding the object;

means for moving the table only in a single direction to maintain the object in imaging alignment with the means for successively imaging the object before and after the means for removing a predetermined layer of material from the object moves into and out of position for removing a layer of material; and

means for moving the material removal station in a second direction substantially perpendicular to the Z axis into and out of relative material removing position in which it removes a pre-determined layer of material.

24. The apparatus of claim 23, in which the data gathering station further comprises means for manipulating data gathered by the imaging means and stored in the data storage means to produce a three-dimensional drawing of the object.

25. The apparatus of claim 23, in which the object is encased within an encasing material to form an encasement and in which the layer removing means removes a predetermined layer of the encasement.

26. The apparatus of claim 23, in which the means for removing a predetermined layer of material comprises an end mill including at least one flute, the end mill being rotated about an axis substantially perpendicular to the axis of motion of the stage and substantially parallel to the common plane, such that a planar surface of the object is exposed by the removal of material by at least one flute as the end mill is rotated.

27. The apparatus of claim 23, in which the removal of the predetermined layer exposes an object surface and an encasing material surface and in which the object surface contrasts with the encasing material surface so that a line of demarcation may be determined between the surfaces.

28. The apparatus of claim 23, in which the predetermined layer is of substantially uniform thickness.

29. The apparatus of claim 23, in which the data gathering station further comprises means manipulating data gathered by the imaging and stored in the data storage means to produce a three-dimensional drawing of the object.

30. A method of scanning a part, comprising:

(a) encasing the part into a potting material to form an assembly;

(b) while the assembly is not moving, progressively horizontally removing a portion of the assembly to expose a surface;

(c) moving the surface substantially only vertically to a position in a fixed position focal plane; and

(d) scanning the surface.

31. The method of claim 30, further comprising repeating (b) and (c) after (d).